config: set default port to 830

Signed-off-by: Petar Koretic <petar.koretic@sartura.hr>
netconf: set default message id to 1

Signed-off-by: Petar Koretic <petar.koretic@sartura.hr>
server: improve message creation

Also fixes argument extraction when message is xml based.

Signed-off-by: Petar Koretic <petar.koretic@sartura.hr>